Decisions, decisions
March 27th, 2009
After waiting months, spending a night lurking in a vault under Geneva earning overtime and coming to the difficult decision to sell some of my other toys that no longer see much usage I can finally afford a new mount. Now comes the really hard part though, what do I get?
The budget is under £1000, the mount needs to carry my 250mm Orion Optics reflector and the 70mm Vixen guide scope and anything else I have hanging off it. The obvious answer then is the Skywatcher EQ6 synscan or syntrek. It will easily carry the load, can be controlled from the laptop, it comes highly recommended, easy choice.
Not quite.
Some considerations need to be looked in to. My pier for instance has a leveling plate and bracket to fit the head off an old EQ5 tripod, thereby allowing me to mount the current horrible old EQ4 mount directly on to it. The EQ6 doesn’t have the same tripod top and I don’t think the bolt holes for the legs will match the bracket on the pier. That means I have to go see my dad and ask him to make me another pier head bracket to replace the one he made me not a month ago.
Secondly I have to use a pier extension to raise the height of the mount to get decent skies, which means I’ll need a new one as my EQ5 half pillar again won’t fit the EQ6.
Trouble and strife.
The easy option is to just get an HEQ5 instead, which will slot right in to the existing pier without any mucking about or need for new parts. Also it costs a lot less and I can then afford to get the guide camera I want as well.
The problem is one of capacity. The rule of thumb is’ over-mount, under-telescope’. Or to put it another way, your payload should be no more than two thirds of your mounts capacity. So lets do the figures.
Orion Optics Europe 250mm OTA – 10kg (say 11kg due to telrad / crayford focuser)
Vixen A70LF Refractor – 2kg
Canon EOS 1000d – 0.5kg
13.5kg total
Counterweights are 5kg each and lets say for arguements sake I use a long shaft and only need one, that still brings the wieght up to 18.5kg, or more than the maximum stated capacity of the HEQ5. The EQ6 on the other hand still has another 7kg to spare.
Decision made I guess.
I’d better call my Dad and get him to warm up the welder.
